Alex and Izzie don't know what the best course of action is going forward, and it's hard to blame them.

Izzie and Alex embrace in the fifth season finale.

Meredith, Cristina and Alex anxiously await the latest update on Izzie's condition.

Miranda Bailey tells Alex how it's going to be as Meredith and Callie look on.

Alex Karev tells Derek not to talk to him like he's a doctor, but instead like he's a friend, and to tell him what to do about Izzie.

What is Alex Karev going to do when it comes to Izzie?

With his new wife ailing, Alex Karev doesn't know what he's gotten himself into.

Alex tends to ailing Izzie in an emotional Season Five scene from Grey's Anatomy. These two have become bigger and bigger characters since the series debuted.

Alex Karev prepares to wed Izzie Stevens in "What a Difference a Day Makes," the 100th episode of Grey's Anatomy. He did so, and with flying colors.

Alex and Izzie are husband and wife.

Alex and Izzie embrace after getting married in the wedding of her dreams - which she originally planned for Meredith!

Alex Karev kisses new wife Izzie Stevens after an emotional exchange of vows and her dream wedding coming to fruition - even though she never intended to be the bride. Bet she's glad she is now!